Missing Sidebar on Some Pages

We are using the Esplanade theme. We are having difficulties with the right sidebar vanishing in Internet Explorer 8. It works fine in Firefox, I believe.

The main pages look fine:
The Home Page
http://unheardbeethoven.urgo.org/wordpress/

The Blog:
http://unheardbeethoven.urgo.org/wordpress/the-unheard-blog/

The problems come when you go to the Search page:
http://unheardbeethoven.urgo.org/wordpress/midis/

That itself looks fine too.

However, if you click any of the searches, in IE 8 you get a result with no right sidebar and the header is squished.
The same result happens when you go to any individual search result. For instance, if you choose Overtures, you get this page:
http://unheardbeethoven.urgo.org/search.php?instrument=3
and if you click on the first entry, you get this page:
http://unheardbeethoven.urgo.org/search.php?Identifier=biam454
neither of which has the right sidebar.

We initially had trouble getting the sidebar to appear at all, but we were able to fix that on the Esplanade Theme Design page for Custom CSS, adding in that box the following code:

#sidebar-right {
    width: 100%;
}

But for some reason, these other pages don’t seem to carry through this custom CSS. A clue that I noticed is that on the pages that do work, the footer reads (c) 1999-2013; on the ones that don’t work, it reads (c) 1999-2012. It’s like there’s some style sheet hiding somewhere that makes IE8 pick up an old version of the page template, before the changes to the Custom CSS and the footer were made. I’m stumped as to where that would be, though. Any ideas? Other folks seem to have noted issues with Word formatting, but I’m not seeing any obvious Word formatting, and we try to always use Notepad to avoid Word issues, but we certainly could have missed something. Thanks.